I may have a second line on some steel pipe. some questions I have are diameter. what do yall think about 24 inch diameter and 4 foot long. also I have questions on the fire box door or lid... I think a door on the side would be better, what do yall think?

I too have a 48" cooking chamber & love it ! plenty of room to spread your meat out ! I thought it was going too be to big but its not , I started to get a 36" chamber but VERY glad I went with the 48" ! My fire box door is on the end not the side .

Are you using 24" pipe for your firebox or a square firebox?Front or back on a square works equally well in my opinion.A top door on a round firebox allows you to utilize the firebox as a grill if you choose but you need to make sure your door seats well or you will lose a lot of heat. There again either will work you just need to make sure you can seal well enough.I built this one years ago it is a 24" x 36" chamber with a 18" x 24" firebox it was very functional.